Grinding-mill rod



March 6, 1928. 1,661,567

w. B. FLOYD GRINDING MILL non Filed Dec. 18. 1924 l ff* i W/A\\\\\ 7l///////////l W/,///A\,\\\\\\\\\\\\\\\\\ 6 2W? i .r

Patented Mar. 6, 1928. l

UNITED STATES vtieren PATENT orifice..

WALTER B. FLOYD, 0F COLUMBUS, OHIO, ASSIGNOR TO THE BONNEYFLOYD COMPANY,

OF COLUMBUS, OHIO, A

oonro'aaeron or GRINDING-MILL ROD.

Application led December This invention relates to a vfabricatedgrinding mill rod, and has for its primary object the provision of a rodconstructed or formed with the end in view of providing efficient andprolonged service and formed so,

.having high abrasive resistant surfaces,

which member is capableof being renewed from time to time as wwear takesplace.

A further object of the invention resides in a. grinding mill rodconsisting of anaxially extending rod or core upon which is mounted aplurality of separable sleeves, the

mounting of the sleeves on the core being so arranged that relativerotation between the sleeves and rod is prevented but the sleeves arecapable of being longitudinally removed from the core upon the releaseof fastening devices which ordinarily function to prevent suchlongitudinal movement.

For a further understanding of the invern tion reference is to be had tothe following description and the accompanying drawing, in which :r

Figure l is a side elevation of a grinding mill rod constructed inaccordance with the present invention. n

Figure 2 is-a vertical sectional view thereof, f

Figure 3 is a transverse vertical sectional view,

Figure 4 is a detail viewof the core,

Figure 5 is a detail view of one of the sleeves constituting the rod,and

Fgure 6 is a detail view of a. modified form of sleeve used inconnection with the rod. v

Figure 7 is a side elevation partly in section of a slightly modifiedform of the invention, p

Figure 8 is a cross-section on the line 8 8 of Figure 7. y

Referring more particularly to the drawings the numeral l designates theimproved grinding mill rod comprisingthe preferred form of the presentinvention. This rod is composed of two ormore distant pieces hav ingdifferent physical characteristics, there being provided a plurality ofreplaceable wearing sleeves' 2, which are formed from a high abrasiveresistant material, such as 18,1924. Serial No. 756,855.

manganese steel, while the axially extending core 3 of the rod is formedfrom a tough, ductile material possessing high tensile strength. It willbe understood that these rods are employed in connection with ,what isknown in the art as a grinding Lmill (not shown). These millsordinarilycomprising i large revolving cylinders capable of receiving therein apredetermined quantity of an ore, or some other similar substance lwhichit is desired to pulverize or disintegrate. The rods l are placed withinthe cylinders loosely', Vso that as the'cylinders are rotated,

the rods will rise and fall contacting withv one another and with thematerial within the cylinders so that saidV materials will be crushedand'disintegrated bythe abrasive action of the rods. Considerabledifficulty has been encountered hitherto in the matter of providing adurable and eilicient rod, which will not crack or brealr under ordinaryservice, and one 4which isf convenient and economical to produce.

It is desirable that a grinding rod of this character should havehardened abrasive resistant surfaces so as to resist the wear whichtakes place when the rods come into contact with the materials to bedisinteg 'ated and with the other rods in the mill cylinders. However,in practiceit has been found that if theserods are formed of uni-` formdensity and vhardened throughout theyy are so brittlethat `breakage'frequently occurs therein from the stresses to which they are subjectedin `the (revolving cylinders `or drums. v Y

To avoid this objection, without'losing durability of the hardenedabrasive rod, the outside layer, or in this instance the sleeves2, ismanufactured in short cylinders orsleeves and then threaded orstacked onthecore 3 which possesses a certain degree of resiliency or flexibilitywhich enables the rod to stand, without breaking, the stresses ofservice. y ,p

Again, prior methods of forming these rods has consisted in casting orrolling the outside layer of high abrasive material on the core ofrelatively soft or of wrought metal. This method Y has certain inherentdisadvantages, theyoutstanding` of which is that the outside hardenedlayer of metal will in practice vary in 'thickness and lack uni formityin diameter throughout the length of the rod. Thus7 these rods inwearing down will wear through the outside layer of hard material andfollowing which the core of softer material will be exposed so that Weartakes place therein very rapidly, so that: the rod will lose itsstrength and resiliency, permitting of the breakinpot' the rod andlosini,T the advantage of empli-ying the central core..

Also, when the outside layer is rolled or caston the core the twomaterials or metals from which they are formed may var v considerably.due to a `di'erent relative rate of expansion and contraction during'heat vtreatment. Frequently the internal strains .thus` set up will alsocause the rods to crack and break overduring manufacture or afterrelatively short; use thereof.

The present construction eliminates the above mentioned faults ordefects in the prior -forms oit' grindingf mill rods described. By4manufacturia;r the hard abrasive resistant material in separate sleevesor cylinders and then Ilongitudinallv alignin} r the same on a toughsteel rod or core. several very important advantages `are obtained.First. the cylinders are ot uniform thickness or diameterv throughoutthe length of the rod; second, the core is sui'liciently tough to holdthe sleeves on the rod .during the lite of the sleeves and third, .amore resilient or elastic rod is provided. In rolling?r over .and overin the ydrum of a grinding mill, the rod 1 will be amply ri gi d `t-ostand all of the strains and at. the same time accomplish more work uponthe material beine ground than the ordinary, cold rolled, rigid rods.

There are several different ways of holding the cylinders or sleeves 2on the inside core 3. In this respect the cores 3 in cross section :arepreferably of hexagonal form. and are received within the `axiallydisi'iosed hexagonal openings 4 `provided in the sleeves or cylinders'2, By this construction 'the ros tation vof the sleeves relativelyr tothe core is eileetivelv precluded. However. it will be obvious that manv other equivalent l'orms ma v he employed tor accomplishing this samepurpose. Such for example as by means of a ltey or pin.

To :prevent longitudinal movement of the sleeves upon the core 3, thelatter in this instance has its ends reduced and threaded as at 5, forthe reception of nuts 6 which are positioned within sockets 7 provided.in the end sections of the sleeves 2. 'To prevent rotation of the nut,the threaded extremity 5 of the eore 3 may be headed as at 8, or atransverse pin 9 may be used for locking the nuts against rotation. Themethod employed. however, for holding the sleeves on the rod or core4must ipossess sutiieient strength so that the assembled rod with thesleeves can he very roughly handled.

It desired the sleeves 2 may be -providedat certa-in of their ends withlongitudinal ipnojections 10, which are adapted Ito be received Withinsockets or recesses 11 iprovided therefor 1n the complcmental ends ofadjacent sleeves. This-construction results in providing an.interlocking connection between the sleeves carried `upon a singlecore. enabl'inx',r the sleeves to co-ordi'nate with one another so as topreclude rotary movement thereof-on the supporting core. Aliso, it willbe Anoted that the sleeves may be provided, as shown 1in Figure 6, withpolygonal exterior surfaces 13, instead of the plain cylindrical form.Other changes of a similar nature may he made, of course,without:departing from ithe spirit of the invention as expressed rinxthe following claims.

lVhat is claimed is:

1. A *grinding mill rod comprising: a steel core, said core beingprovided with ipolvgzo nal surfaces, a plurality of high abrasive rensistant steel sleeves having axially disposed polygonal sided openingsextendingr thcrethrough and adapted to `receive said core.v andfastening appliances provided in connection with the 'ends Vof said corenoriuall)` preventing longitudinal movement of the sleeves on said core.

2. In a -device of the character -descri-hed. an axially extendingrcore. a plurality7 -otsleeves formed from a high-abrasive resistantsteel mounted upon said core, and interloilkA iner connections betweenIthe adjoiningr end portions of said sleeves.

In testimony whereof l atlix any signatul e.

'WALTER B. FLOYD.

